This invention relates to an inflatable support appliance and in particular to a portable, light-weight, easy to maintain and clean gaseous mixture inflatable support therapy cushion.
It has long been known that an unfortunate side effect of being compelled to lie relatively immobile due to injury or infirmity, is the manifestation of decubitus ulcers, known popularly as "bed sores", on the body dermis which experiences unrelieved contact with a firm surface. These ulcerations which serve to only further debilitate the prone patient, are caused by the combined effects of disrupted peripheral blood circulation and moisture accumulation at the sites of such firm body surface contact. The potential formation of decubitus ulcers requires that a patient, such as a hospital, out-patient or nursing home occupant, being unable to adjust his or her own posture without assistance, must be manually repositioned at frequent intervals around the clock for as long as such relative immobility persists.
Air beds have been used to support immobilized patients and several types of air support appliances are known. However, currently available air support appliances are cumbersome and expensive, requiring considerable ancillary apparatus such as a conventional bed frame, base boards, bellows and drawsheets. Mechanical and structural complexity, such as the incorporation of numerous conduit paths, header chambers, tubular members, plenum chambers and multiple layers of material between mattress and user, characterizes many of the air support systems previously known.
Experience with existing inflatable mattresses has revealed a number of shortcomings: they are difficult to transport, set up and maintain and are costly, there being a high purchase price for the support mattress and ancillary equipment. These and other drawbacks are believed to make air mattress use prohibative for many nursing homes, small hospitals and in home care. Moreover, no wide selection of sizes and shapes are available at a low cost with ease of set up and maintenance.
To the inventors' knowledge, there does not exist at this time any apparatus such as the present invention which alleviates the conditions causing bed sores or can treat a wide variety of dermal problems such as abrasions, burns, wounds or lacerations and thereby provide for general skin care and allows for individual air cushion pressure control, is available in a variety of shapes and sizes and yet remains extremely portable, easy to maintain and clean and removes the need for any external frame. As those in the field are aware, in the United States alone there are each year millions of potential users of such a support appliance. Several issued patents demonstrate the shortcomings of existing systems.
Scales U.S. Pat. No. 3,822,425 issued Jul. 9, 1974 is directed to an inflatable support appliance made of material that has water vapor permeability with limited air permeability, but is non-permeable to solids and liquids. As disclosed, Scales teaches the use of an external structural support such as a bed frame. The air cells have a two part (cap unit and trough) structure and have the claimed important feature of allowing for the permeability of water vapor from the outside to the inside of the air cell's surface. An outlet port to exhaust air from the system is also required.
Hunt et al, U.S. Pat. No. 4,488,322 issued Dec. 18, 1984 and its continuation, Hunt et al, U.S. Pat. No. 4,525,885 issued Jul. 2, 1985 both show an air support mattress containing a plurality of inflatable air sacs requiring an external supporting bed frame. The Hunt patents preferably require constructing the air sacs of air impermeable and water vapor permeable material.